2007 Holden Commodore Warning message

This particular problem surfaced some months ago and ended up with the computer shutting down the engine.
An engine block sign with a lightening bolt in the middle shows on the dash with a corresponding orange symbol to the right and a message saying "Check Drivetrain".
The roadside assist mechanic reset the computer using a diagnostic tool after checking all the basics.
It has come up again, so I figure it must be a faulty sensor somewhere in the system.
I noticed today that it came up after I put the car into neutral to stop the clunking in the rear I asked about earlier.
It may just be a coincidence.
I disconnect the battery for a few minutes to reset the computer and that stops the problem for a while.
I'm very limited with funds, so that's why I'm asking you instead of taking it to a repairer.
Perhaps there's something I can do to correct the problem.
U.S. Code scanners don't work on Aussie cars, otherwise I'd simply connect the cheap one I mistakenly bought on line and fix the hassle.
Hope you can help.